Male and Female 27 



and so the process continues until by night each 

 egg may have changed into a Httle spherical 

 mass of perhaps a hundred or more cells. 

 Meanwhile this mass of cells is growing larger. 

 In the course of a couple of days it elongates 

 and one can begin to make out the difference 

 between future head and body. In another 

 day the little tadpoles begin to wiggle out of the 

 jelly, and soon they are swimming about seek- 

 ing food. How they grow, develop legs, and 

 absorb their tails as they change to the adult 

 frog is known to almost every boy and girl, but 

 it is a process that is always watched with 

 interest. This change from a fishlike creature 

 that swims in the water and feeds on vegetable 

 matter to an insect-eating, air-breathing animal 

 is one of the everyday marvels. The whole 

 life-history, briefly outlined above, may be seen 

 if a few of the eggs in their jelly are put into a 

 quart fruit jar or other convenient dish that is a 

 third full of water together with some of the 

 green water weeds found growing in the pond or 

 stream. When the tadpoles are fairly good sized 

 the water should be reduced in amount so it is 



